• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1372-1374
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• 2001

This paper describes fabrication and characteristics of metal thin-film pressure sensor for working at high temperature. The proposed pressure sensor consists of a chrom thin-film, patterned on a Wheatstone bridge configuration, sputter-deposited onto thermally oxidized Si membranes with an aluminium interconnection layer. The fabricated pressure sensor presents a low temperature coefficient of resistance, high-sensitivity, low non-linearity and excellent temperature stability. The sensitivity is 1.097 $\sim$ 1.21 mV/V kgf/$cm^2$ in the temperature range of 25 $\sim$ $200^{\circ}C$ and the maximum non-linearity is 0.43 %FS.

• Journal of the Korean Institute of Telematics and Electronics
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• v.15 no.3
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• pp.11-17
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• 1978

A medium scale integrated circuit, BCD to seven segment decoder/driver is designed and fabricated by employing P-channel metal-oxide-semiconductor technology. The device configuration is specifically designed for a common cathode seven segment LED display unit. The decoder logic is composed of two serially connected read-only-memory matrices and the LED drivers are implemented with wide channel FET's. The fabricated integrated circuit performed successfully with a supply voltage between -7 Volt and -26 Volt and the non-uniformity of the LED segment current is about 10%.

• Journal of Environmental Health Sciences
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• v.10 no.1
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• pp.33-45
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• 1984

In order to investigate the pollution of heavy metal in soil, chinese cabbage and radish collected from Singal interchange (highway area), Anyang stream, Jungryang stream (stream basin) and Chunchun dong, Suweon (non-polluted area), this study was carried out from July to October in 1983. The contents of cadmium, copper, lead, and zinc were determined by atomic absorption spectrqphotometry. Generally in soil, the contents of heavy metals in highway area were lower than that in Anyang stream and Jungryang stream, but higher than that in non-polluted area. (Chunchun dong, Suweon). The vegetable samples of highway area were more polluted compared with that of Chunchun dong, Suweon. The contents of heavy metals in radish were higher than that of chinese cabbage and radish leaves were more polluted than roots.

• Advances in nano research
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• v.3 no.1
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• pp.49-54
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• 2015

The structure represents symmetrical metal electrode (gate 1) - front $SiO_2$ layer - n-Si nanowire FET - buried $SiO_2$ layer - metal electrode (gate 2). At the symmetrical gate voltages high conductive regions near the gate 1 - front $SiO_2$ and gate 2 - buried $SiO_2$ interfaces correspondingly, and low conductive region in the central region of the NW are formed. Possibilities of applications of nanosize FETs at the deep inversion and depletion as a distributed capacitance are demonstrated. Capacity density is an order to ${\sim}{\mu}F/cm^2$. The charge density, it distribution and capacity value in the nanowire can be controlled by a small changes in the gate voltages. at the non-symmetrical gate voltages high conductive regions will move to corresponding interfaces and low conductive region will modulate non-symmetrically. In this case source-drain current of the FET will redistributed and change current way. This gives opportunity to investigate surface and bulk transport processes in the nanosize inversion channel.

• Korean Journal of Organic Agriculture
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• v.9 no.3
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• pp.85-92
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• 2001

The effect of Dolichos lablab leave extract on enzyme activities in mice blood was investigated in this study to clarify the new useful application of the Plant leaves. There were not significant differences in the enzyme activities in mice blood among treatment fed with the leave extract and non fed control. The feeding treatment with the extract showed a tendency to activity compared to the nun fed control. The activities of glutamate oxaloacetate transaminase, glutamate pyruvate transaminase and lactate dehydrogenase in mice blood at the treatment fed with lead and the leave extract were significantly low compared to their activities at the non fed treatment with the extract, respectively. The choline esterase activity was high at the leave extract feeding. The cadmium dietary treatment showed the same result as the lead treatment. In conclusion, the physiological function of the Jebikong leave was significantly in creased when the mice was stressed by the hear metal intake. Therefore, the plant leave extract would consider the reduction of heart metal effect.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.651-656
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• 1999

This study was carried out to investigate the paddy soil and water quality in Boryung freshwater reservoir watershed during the non-cropping season. Soil pH of the Boryung freshwater reservoir watershed were 5.39∼5.78. Total-N and P contents were high by the accumulation of chemical fertilizer partly. Heavy metal content of paddy soils were natural background level. Water pH of the Boryung freshwater reservoir watershed ranged from 6.82 to 8.64. Total-N content affected by a livestock wastes and sewage water were the higher than that of others and total-P content showed below 0.1mg/L. Nitrate nitrogen contents was very high according to the influence a livestock waste and sewage water partly. Heavy metal contents of wateers were natural background level.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05a
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• pp.192-196
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• 2002

This paper describes on the fabrication and characteristics of a metal thin-film pressure sensor based on Cr strain-gauges for harsh environment applications. The Cr thin-film strain-gauges are sputter-deposited onto a micromachined Si diaphragms with buried cavity for overpressure protectors. The proposed device takes advantages of the good mechanical properties of single-crystalline Si as diaphragms fabricated by SDB and electrochemical etch-stop technology, and in order to extend the operating temperature range, it incorporates relatively the high resistance, stability and gauge factor of Cr thin-films. The fabricated pressure sensor presents a low temperature coefficient of resistance, high-sensitivity, low non-linearity and excellent temperature stability. The sensitivity is 1.097~1.21 $mV/V{\cdot}kgf/cm^2$ in the temperature range of $25{\sim}200^{\circ}C$ and the maximum non-linearity is 0.43 %FS.

• Korean Journal of Metals and Materials
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• v.47 no.3
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• pp.182-187
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• 2009

The molten salt electrolysis is applied to reduce titanium dioxide to titanium metal using calcium chloride as an electrolyte and the reaction mechanism of the reduction process is examined by analyzing the reaction products. The process conditions to obtain titanium metal for $900^{\circ}C$ correspond to 2.9~3.2 V and 24 hours. The reaction products for 2.9 V at $900^{\circ}C$ include irregular-shaped titanium oxides such as $Ti_4O_7$, $Ti_3O_5$ and $Ti_2O_3$ and polyhedral $CaTiO_3$. Using these microstructure analysis, the sequential reaction mechanism for the electrochemical reduction of titanium dioxide to titanium is proposed.

• Journal of Korea Foundry Society
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• v.43 no.1
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• pp.3-10
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• 2023

This study was conducted to develop technology that can detect stomatal defects inside nonferrous metal products that may occur during die casting processes. Through this research, we intend to detect possible pores in the products in advance, block the distribution of defective products, and contribute to reducing possible losses due to damage to distributed products.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10a
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• pp.277-280
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• 2003

It was investigated that the "ㄱ" type angle product could be bended with a curvature during extrusion by extru-bending process. The bending process for the "ㄱ" type angle product can be developed by the hot metal extru-bending machine with the two punches moving in the different velocity. Because of non-symmetry of product, it is important to design the ruled surface contour of dies cavity for the welding and bending with two billets. So it is designed that the multi-hole container has two non-symmetric holes and non-symmetric contour of dies entrance. The results of the experiment show that "ㄱ" type angle product can be bended by the extrusion process and that the curvature of the product can be controlled by the velocity of punch and that the defects such as the distortion of section and the thickness change of the product and the folding and wrinkling of the product did not happen after the bending processing by the extrusion bending machine.